Description Of The Prior Art
The use of tapping machines for tapping openings in pipelines is well known. Prior issued U.S. Pat. No. 3,614,252 entitled "Tapping Apparatus"; U.S. Pat. No. 4,579,484 entitled "Underwater Tapping Machine"; and U.S. Pat. No. 4,880,028 entitled "Completion Machine" are exemplary of such devices. The contents of these prior issued United States patents are incorporated herein by reference.
The prior patents illustrate and describe techniques for tapping into a pipeline while under pressure without interrupting transportation of gases or liquids through the pipeline. Although the basic operation as set forth below remains the same, this invention improves the operation in several ways, as set forth below, that work to increase the tapping apparatus' operating range and to provide energy efficient speed controls.